Novel method of derivatization of an amidinourea (lidamidine) for GLC analysis.

A new quantitative GLC method for analysis of lidamidine hydrochloride (I) was developed. The method was based on derivatization of I to 1-(2,6-dimethylphenyl)-4-methylamino-dihydro-1,3,5-triazin-2-one (II) using dimethylformamide dimethylacetal reagent. Compound II was synthesized and characterized by IR, NMR, mass spectrometry, and elemental analysis.

Characterization of impurities in sulfasalazine.

The chemical structures of four impurities isolated from sulfasalazine were determined. Three impurities are the by-products of the reaction process in drug synthesis, i.e.

Hydrolytic degradation of 2,6-dichlorobenzylthiopseudourea hydrochloride.

Degradation of 2,6-dichlorobenzylthiopseudourea hydrochloride was followed in basic medium (pH 7.5) to isolate and characterize all possible degradation products. IR, Raman, and NMR spectroscopy, TLC, and elemental analysis were used to identify the products.

Analytical-physical profile of lidamidine hydrochloride (WHR-1142A), a novel antidiarrheal agent.

The structure elucidation, physical and chemical parameters and hydrolysis kinetics of 1-(2,6-dimethylphenyl)-3-methylamidinourea hydrochloride (WHR-1142 A, lidamidine hydrochloride), a novel antidiarrheal agent, were determined. The stability of the substance in aqueous solution (pH 1-13) was studied at 50 degrees, 65 degrees and 80 degrees C.

Antimotility and antisecretory activity of some aryl substituted amidinoureas.

A number of aryl substituted amidinoureas have been prepared and examined for their gastrointestinal spasmolytic, antimotility, antidiarrheal and antisecretory effects. In general, antisecretory and antimotility effects have been found to be associated with each other in these compounds. The structure-activity relationships found show that substitution of the aromatic ring in positions other than 2 and 6 correlates poorly with potency, and potency of such compounds is low.

Kinetics of hydrolysis of fenclorac.

The kinetics of hydrolysis of fenclorac were studied to determine its stability in aqueous solution at different pH's and temperatures. For this study, a stability-specific liquid chromatographic assay method was developed to separate fenclorac from its hydrolysis product, alpha-hydroxy-3-chloro-4-cyclohexylbenzeneacetic acid. The k-pH profile in the 0-12 pH range in various buffer solutions shows that fenclorac is stable in its undissociated form in strongly acidic media and is unstable in neutral and alkaline media.